Google Webmaster Tools:
Google Webmaster Tools provides you with detailed reports about your pages' visibility on Google. To get started, simply add and verify your site and you'll start to see information right away.
Google Analytics is the enterprise-class web analytics solution that gives you rich insights into your website traffic and marketing effectiveness. Powerful, flexible and easy-to-use features now let you see and analyze your traffic data in an entirely new way. With Google Analytics, you're more prepared to write better-targeted ads, strengthen your marketing initiatives and create higher converting websites.
Google Website Optimizer:
Website Optimizer, Google’s free website testing and optimization tool, allows you to increase the value of your existing websites and traffic without spending a cent. Using Website Optimizer to test and optimize site content and design, you can quickly and easily increase revenue and ROI whether you’re new to marketing or an expert.
Google Zeitgeist is a snapshot in time of what people are searching for on Google all over the world. It's an interesting way to people-watch, and since Google is the most-used search engine on the Web, it's a great way to get some behind the scenes (kind of) data and statistics on what people are searching for.
Reflects what keywords people are searching for on a daily basis.
Google Insights for Search:
Google Insights for Search, you can compare search volume patterns across specific regions, categories, time frames and properties.
Google Traffic Estimator:
Google's Traffic Estimator tool is a good way to get an idea of how much a new campaign is likely to spend once it is launched.
Google Keyword Tool:
Enter one keyword or phrase per line to see what related word searches your ad will show on.
Google Ad Planner:
Official Ad Planner Help Center where you can find tips and tutorials on using Ad Planner and other answers to frequently asked questions.
Access your Bookmarks on any computer, and use Lists to share them with friends.
Read them in one place with Google Reader, where keeping up with your favorite websites is as easy as checking your email.
Google Alerts are email updates of the latest relevant Google results (web, news, etc.) based on your choice of query or topic.
Aggregated headlines and a search engine of many of the world's news sources.
Start conversations about the things you find interesting. Share updates, photos, videos and more with your friends.
Decide what the world sees when it searches for you. Display the information you care about and make it easy for visitors to get to know you.
Google Places for Business to get your business found on local search results on both Google Search and Google Maps.
Google +1 button:
The +1 button is shorthand for "this is pretty cool" or "you should check this out." Click +1 to publicly give something your stamp of approval.
Google Correlate finds search patterns which correspond with real-world trends.
Google website speed check:
Evaluates the performance of web pages and get suggestions on how to improve them.
Google url shorter:
Google URL Shortener at goo.gl is used by Google products to create short URLs that can be easily shared, tweeted, or emailed to friends.
FeedBurner is provides media distribution and audience engagement services for blogs and RSS feed.